Centrifugal pumps



3, 1965 J. J. YUZA ETAL 3,198,125

CENTRIFUGAL PUMPS Filed July 14. 1960 2 Sheets-Sheet 1 INVENTORS: JOSEPH J. VUZA RUDOLPH A. YUZA BY m, WM/M EiL g- 1965 J. J- YUZA ETAL CENTRIFUGAL PUMPS 2 Sheets-Sheet 2 Filed July 14, 1960 INVENTORS: JOSEPH J. YUZA RUDOLPH A. YUZA United States Patent 3,193,125 CENTRKFUGAL PUMPS Joseph I. Yuza, 3816 W. 64th St, Chicago, Iii, and Rudolph A. Ynza, 1191i Buckingham, Westchester, Ill.

Filed July 14, 1960, er. No. 42,784 8 (Ilaims. (Cl. 1;(l387) This invention relates to centrifugal pumps, and particularly t-o centrifugal pumps which are relatively small in overall size.

The pump of the present invention utilizes a rotary impeller and is especially intended for pumping and circulating liquids in various kinds of associated apparatus. By way of example, in one specific application the pump of the present invention can be utilized to circulate the liquid in a fruit juice dispensing device or other similar dispenser. The pump of the present invention also incorporates an electric drive motor as an integral part thereof.

The pump of the present invention incorporates a magnetic coupling in the drive between the electric motor and the rotary impeller. Moreover, advantage is taken of the absence of a physical connection afforded by the magnetic coupling to construct the pump in two separate and distinct assemblies. it is a primary object of the present invention to group in one assembly and to permit ready access to those parts of the pump which may require periodic servicing or inspection while enclosing the other parts of the pump, particularly the motor, in another assembly.

A pump constructed in accordance with the present invention comprises a base assembly and a pump head assembly. The base assembly includes a multiple-part housing which i substantially completely filled with oil. An electric motor is mounted in the housing and is com plctely immersed in the oil. A first magnetic member, which preferably includes two or more permanently magnetized pole pieces of opposite polarity mounted adjacent one another, is connected for rotation by the motor and is also disposed within the housing. The pump head assembly includes an outer casing in which an impeller is rotatably mounted, and the casing as well as the impeller are removably mounted on the base assembly. Inlet and outlet conduits are formed in the casing for conducting fluid to and from the impeller. The pump head assembly also includes a second magnetic member associated with the impeller and magnetically coupled to the first magnetic member for rotating the impeller therewith. A pump construction incorporating these structural features constitutes another object of the present invention.

It is a further object of the present invention to hermetically seal the multiple-part housing of the base assembly to prevent leakage of oil therefrom and to prevent the entry of foreign assembly.

It is another object of the present invention to form the blades of the impeller integral with the above-noted second magnetic member to achieve a one-piece part and thereby simplify the manufacture and assembly of the pump.

It is a matter of considerable interest to a manufacturer of pumps of the kind to which this invention relates that the pump perform satisfactorily in service. In the past it has been found that a principal cause for complaints of unsatisfactory performance could be traced to unnecessary tampering with the motor structure of the pump.

It is therefore another object of the present invention to so assemble the base assembly of the pump as to minimize the possibility of tampering with the motor structure matter into the interior or the base by someone unfamiliar with the construction and operation of the pump or otherwise not qualified to service the pump.

It is a related object to prevent unnecessary tampering with the motor while also accomplishing the above-noted hermetic sealing of the multiple-part housing by bonding epoxy resin to the separate parts of the housing at the areas of juncture of the separate parts with one another.

It is yet a further object of the present invention to include a novel lubricating arrangement in the pump head assembly whereby the fluid to be pumped also serves to lubricate the bearing structure for the impeller.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawing which, by way of illustration, show a preferred embodiment of the present invention and the principles thereof and what is now considered to be the best mode contemplated for applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art Without departing from the present invention.

In the drawings:

FIG. 1 is an elevation view in section through a centrifugal pump constructed in accordance with one embodiment of the present invention;

FIG. 2 is a perspective view of the exterior of the illustrated in FIG. 1;

FIG. 3 is a fragmentary enlarged view in section showing details of assembly of a part of the pump illustrated in FIG. 1; and

FIG. 4 is a plan view of a seal plate utilized in the pump illustrated in FIG. 1 and illustrates the disposition of the seal plate with respect to a service cord locknut in the assembled pump.

In FIGS. 1 and 2 a centrifugal pump constructed in accordance with one embodiment of the present invention is indicated generally by the reference numeral 11. The centrifugal pump 11 comprises a base assembly 12 and a pump head assembly 13. The base assembly 12 includes a multiple-part outer housing afforded by a generally cylindrical-shaped case 14, a top cover plate 16 and a seal plate 17. In a commercial form of the pump the cover plate 16 is composed of stainless steel while the case 14 is composed of a suitable light metal, such as aluminum. However, other suitable materials can be utilized without departing from the present invention.

The housing thus afforded by these three parts is substantially completely filled with oil, as indicated by the legend in FIG. 1, to the approximate level illustrated in FIG. 1. An electric motor M of any suitable type, such as a conventional shaded-pole motor, is mounted in a fixed position within the interior of the case 14 by mounting brackets which are not illustrated in FIG. 1. The motor M is preferably completely immersed beneath the surface of the oil. Lead wires W are attached to the motor M and extend upwardly through a suitable opening 18 in the cover plate 16. Insulating sleeves 19 shield the portions of the wires W which extend between the opening 18 and the points of connection to the motor M. The portion of the cover plate 16 extendingaxially above the opening 8 is formed with a counterbore 21, which is partially threaded as indicated by the reference numeral 22.

An adapter 23 is disposed within the tapped portion of the counterbore. The adapter may preferably be formed of any suitable plastic resin. The upper ends of the wires W are embedded in the adapter and are connected to corresponding wires in a service cord 24 which is provided for connecting the pump to electric mains. As illustrated in FIG. 1 the adapter 23 is effective to engage and compress an O-ring 26 into sealing relation with pump P} c.) the shoulder afforded by the counterbore 21. The adapter 23 also includes an upwardly projecting sleeve 238 which serves to protect the enclosed portion of the service cord 24. A loclmut .27 is also threaded within the tapped portion of the counterbore 2-1 to prevent the adapter 23 from working loose therein.

The base assembly 12 also includes a first magnetic coupling member 31 which is connected for rotation by the motor M. Thus, a drive shaft 32 projects upwardly from the motor M and is formed with a reduced diameter end portion 3?, and an annular shoulder 33. The shaft 32 is journalled for rotation within a ball bearing 34. The inner race 36 of the bearing is positioned to abut the annular shoulder 33 so that the ball bearing 34 can be effective to take up axial thrust of the drive shaft 32 in an upward direction, as indicated by the arrow A in FlG. l, for a reason that will become more apparent from the description which follows.

A driver bushing 37 is concentrically disposed about the reduced diameter end portion 32' of the drive shaft and includes a radially projecting flange 37F. The driver bushing 37 is disposed within a central opening 38 of the first magnetic coupling member 31, and a cap screw 39 projects through a suitable opening formed in an end of the driver bushing 37 and is threaded within the free end of the drive shaft 3 2,. T e cap screw 39, in conjunction with the washer 41 and the flange 37F, serves to retain the coupling member 33. in a fixed axial position with respect to the drive shaft 3".

In this instance the first magnetic coupling member 31 is a permanent magnet of annular configuration and comprises a plurality of pole pieces of opposite polarity disposed in spaced relation to one another within the annulus of the magnetic member 31. Any desired number of pole pieces can thus be utilized. In the commercial form of the present invention six pole pieces are utilized in an arrangement wherein three pole pieces of one polarity, as indicated by the reference character S in FIG. 1, alternate with three pole pieces of an opposite polarity, as indicated by the reference character N in FIG. 1. Preferably the greater portion of the magnetic member 31 is disposed below the level of the oil within the base assembly 12. This disposition of the magnetic member 31 in the oil bath has been found to contribute in a signiflcant manner to lower operating temperatures in the base assembly 12.

In accordance with the present invention the separate parts affording the outer housing of the base assembly, the case ltd, the cover plate 16, and the seal plate ll? are bonded together to form what is in effect a unitary structure. For this purpose epoxy resin, indicated by the reference character R, is bonded to the adjacent surfaces of the separate parts of the housing at each of the areas of juncture of the separate parts with one another. In actuality the epoxy resin R forms a film of minimal thickness. However, the thickness of the film has been exaggerated in FIG. 1 for purposes of illustration.

With particular reference to FIG. 3, a preferred construction of the cover plate 16 which facilitates a secure sealing and bonding between the case 14 and the cover plate 16 is illustrated. In this instance the cover plate 16 is formed with an annular depending flange 41 adapted to fit within the open upper end of the case 14. The flange 41 is offset slightly from the outermost edge of the cover plate In to afford a shoulder 4t) adapted to reside on the upper edge of the case 14. The outer surface 42 of the flange, that which faces the inner surface of the case lid, is tapered inwardly at a slight angle from the vertical so as to define a wedge-shaped annular chamber with the side wall of the case I14. Additionally, the free end of the depending flange ll is formed with an inclined surface as indicated by the reference numeral 43. It has been found that these dispositions of the surfaces 42 and 43 significantly contribute to a more uniform distribution of the resin R between the areas of juncture of the case M and the cover plate 16 and enable a highly effective bonding and sealing between these two parts to be obtained. As in the case of the thickness of the film of epoxy resin R as noted hereinabove, the inclination of the surfaces 42 and 43 has been somewhat exaggerated for the purposes of illustration. in a commercial form of the present invention, an inclination of three degrees for the surface 4?; and ten degrees for the surface 43 has been found to be quite satisfactory.

As illustrated in FIG. 3 the upper surface of the cover plate to may be formed with an inner groove as for the reception of a sealing ring 47. In this case the epoxy resin R is also bonded to the sealing ring 47. The seal plate 17 is attached to the cover plate 16 by a number of shoulder screws 51. Thus, as best illustrated in FIG. 1 each shoulder screw 51 is formed with an end 51' of reduced diameter which affords a shoulder 52 effective to engage the upper surface of the seal plate ll? about the periphery of circular openings through which the reduced diameter ends Eli are passed. The cover plate 16 is formed with internally threaded openings 55 for receiving the threaded ends of the shoulder screws 51, and each of these threaded openings is preferably counterbored, as indi ated by the reference numeral 57, so that a film of epoxy resin can be bonded to the unthreaded part of the reduced diameter ends 51'.

Epoxy resin is also preferably applied between the driver bushing and the central opening 38 in the magnetic member 31 to bond these parts together. Likewise, epoxy resin is utilized to bond the service cord lochnut to the adjacent sleeve of the adapter 23 and to the cal plate 17, as illus.; .ted in 1. Also, he scal plate 7 is preferably provided with an arcuate recess 61 for accommodating the sleeve However, the arcuate recess 61 is preferably of somewhat smaller diameter than the service cord loclrnut 2'? (see FlG. 4) to thereby aflord an additional safeguard against any attempted disassembly of the base assembly Epoxy resin is also preferably extended across the opening 13 in the cover plate ltd in the manner indicated by the reference numeral 62 in FIG. 1.

The base assembly 12 also includes a bearing pin 63) which projects upwardly from the outer surface of the seal plate lid, and which is adapted to support the impeller structure of the pump head assembly B, as presently described. The impeller bearing pin 63 is retained in position by a cap screw 6d which projects through an opening 6d in the seal plate 17. A bead 67 of solder or the like is preferably laid around the entire periphery of the head of the cap screw as to seal off the opening 66. Thus, the entire base assembly 12 is hermetically sealed in a manner such that unwarranted tampering with the inner mechanism of the base assembly 122 is rendered virtually impossible.

The pump head assembly 13 includes an outer casing 71 which is preferably molded from nylon or like plastic material, but may also be fabricated from stainless steel or other suitable metal. A series of cylindrical openings '72 are formed in the casing 71 at locations corresponding to the positions of the shoulder screws 51. Thus, the casing 71 is removably mounted on the base assembly 12 by nuts '73 threaded on the upper end portions of the shoulder screws 51. A gasket 74 is preferably interposed between the casing "ill and the seal plate 17 as illustrated in FIGS. 1 and An impeller 'Fd, Wl'llCh ineludes blades '77, is mounted for rotation on the bearing pin 63 for pumping fluid from an inlet 78 through an outlet 79. Preferably, and as illustrated in H6. 1, the inlet and outlet conduits for the pump are molded intogrally with the casing '71. The inlet 78 is axially aligned with the central opening Si in the impeller '76 for directly supplying fluid thereto. The outlet '79 is tangentially disposed with respect to the periphery of the impeller '76 as illustrated in FIG. 2.

A bearing is interposed between the impeller lad c0 7d and the bearing pin 63. The bearing 82 is preferably molded from a phenolic resin and may be impregnated with graphite. The bearing 82 is a sleeve-type bearing but includes an end cap 82C which extends over the free end of the bearing pin 63 between the bearing pin and the adjacent part of the impeller is. Also, the hearing 82 includes a radially projecting flange 82?, and the end cap 82C and flange 82F serve to absorb the axial thrust exerted by the impeller 76 in the direction of the arrows B in the course of operation of the pump ll, as will become more apparent from the description to follow.

The pump head assembly 13 also includes a second magnetic coupling member 84 which is generally similar in construction to the first magnetic member 31 described hereinabove in relation to the base assembly 12. Thus, the magnetic coupling member 84 is a permanent magnet that is generally annular in configuration and includes a number of spaced pole pieces of alternate polarity. Thus, a pole of one polarity, indicated by the reference character S in FIG. 1, alternates with a pole of opposite polarity, indicated by the reference character N in FIG. 1. The annular magnetic members 31 and 84- are axially aligned with one another in the assembled pump H with pole pieces of opposite polarity disposed in vertical relationship by reason of the magnetic attraction therebetween. Rotation of the first magnetic coupling member 31 by the motor M tends to rotate the second magnetic member coupling 84 in the same direction and at the same angular velocity. Thus, the two coupling members 31 and 84 afford a magnetic coupling that completes a driving connection between the pump motor and impeller with no physical connection therebetween.

The impeller 76 and the magnetic member 84 are preferably fabricated as an integral one-piece part to simplify the manufacture and assembly of the pump ll. Also, the magnetic member 84 is formed with a shoulder 86 adapted to receive the flange $21 of the bearing, and a film of epoxy resin R is preferably applied between the adjacent surfaces of the bearing 82 and the impeller and magnetic member to bond these parts together.

In accordance with the present invention, means are incorporated in the pump head assembly 13 for lubricating the bearing surfaces of the bearing 82 and the impeller bearing pin 63 by the same fluid that is to be pumped between the inlet 78 and the outlet 79. Thus, the cap 82C is formed with an opening 91 which effectively connects the interior of the bearing $2 to the inlet opening 81 in the impeller. This opening 91 thus affords a passageway for distributing fluid about the surface of the impeller bearing pin 63 to afford lubrication between the pin 63 and the bearing 82.

In operation, the fluid to be pumped is introduced through the inlet 78 to the interior of the impeller 76. The impeller 76 is rotated by the motor M through the magnetic coupling afforded by the magnetic members 31 and 84 so that blades 77 impel the fluid radially outwardly and through the outlet 7%. If there should be any malfunctioning of the pump 11, as by the impeller becoming clogged or the like, the pump head assembly 13 can be readily removed from the base assembly 12 merely by removing the nuts 73 and lifting the casing 71 from the shoulder screws 51. in this manner ready access is provided to the impeller '76 as well as to the interiors of the conduits 73 and 79. Additionally, the impeller and magnetic member can be lifted f om the bearing pin as if necessary. After the malfunctioning has been remedied, the pump lll can be just as quickly reassembled and returned to operation.

As noted hereinabove, the pump it incorporates specific structural features which are adapted to take into account the axial thrust developed by the magnetic attraction of the magnetic members 31 and 84. Thus, the base assembly 12 incorporates a shoulder 33 and a ball bearmg 34 for taldng up this thrust in the base assembly 12, and the bearing 82 includes the cap 82C and the flange d 82? for compensating for this thrust in the pump head assembly 13.

Thus, in accordance with the present invention a centrifugal pump it utilizes a magnetic coupling between a drive motor and the impeller to enable a novel and benelicial two assembly construction to be realized. A drive motor and related parts, which are not likely to malfunction even after long continued periods of operation, are mounted within a base assembly and are protectively secured therein. The rotary impeller and related parts, which may require periodic servicing or inspection, are included in a separate pump head assembly which may be readily removed from'and replaced on the base assembly with a minimum expenditure of time and effort.

Hence, While I have illustrated and described the preferred embodiment of our invention, it is to be understood that this is capable of variation and modification.

We claim:

l. A centrifugal pump comprising: a base assembly which includes a hermetically sealed housing substantially completely filled with oil, a motor mounted within the housing and immersed within the oil, and first magnetic means connected for rotation by the motor and disposed within the housing; and a pump head assembly removably mounted on the base assembly, said pump head assembly including an outer casing, an impeller mounted for rotation within the casing, inlet and outlet conduit means for conducting fluid to and from said impeller, and second magnetic means associated with the impeller and magnetically coupled with the first magnetic means for rotating the impeller therewith, at least one of said magnetic means consisting essentially of an annular member of permanent magnet material having axially projecting pole pieces magnetized in an axial direction at a plurality of spaced points about the periphery thereof.

2. A centrifugal pump comprising: a base assembly which includes a multiple-part housing, sealing means for hermetically sealing said housing and integrally joining the multiple parts thereof including an epoxy resin bonded to the separate parts of the housing at the areas of juncture of the separate parts with one another, a motor mounted within the housing, and first magnetic means connected for rotation by the motor and disposed within the housing; and a pump head assembly removably mounted on the base assembly, said pump head assembly including an outer casing, an impeller mounted for rotation within the casing, inlet and outlet conduit means for conduct-ing fluid to and from said impeller, and second magnetic means associated with the impeller and magnetically coupled with the first magnetic means for rotating the impeller therewith, at least one of said magnetic means consisting essentially of an annular member of permanent magnet material having axially projecting pole pieces magnetized in an axial direction at a plurality of spaced points about the periphery thereof.

A centrifugal pump comprising: a base assembly which includes a multiple part housing formed with an opening for electrical lead wires, an electric motor mounted within the housing, electrical lead Wires extending from the motor through said opening for connecting the motor with a source of electrical power, sealing means for hermetically sealing said housing and integrally joining the multiple parts thereof including an epoxy resin bonded to the separate parts of the housing at the areas of juncture o-f the separate parts with one another and also extending across said opening and bonded to the wires proectmg therethrough, and first magnetic means connected for rotation by the motor and disposed within the housing; and a pump head assembly removably mounted on the base assembly, said pump head assembly including an outer casing, an impeller mounted for rotation within the casing, inlet and outlet conduit means for conducting fluid to and fromsaid impeller, and second magnetic means associated with the impeller and ma netically c Med with the first magnetic means for rolat-ing the im- 951161' theft/With, at least one of said magnetic means consisting essentially of an annular member of permanent magnet material having axially projecting pole pieces magnetized in an axial direction at a plurality of spaced points about the periphery thereof.

A centrifugal pump comprising: a base assembly Which includes a hermetically sealed housing, a motor mounted within the housing, and first magnetic means connected for rotation by the motor and disposed within the housing; and a pump head assembly removably mounted on the base assembly, said pump head assembly including an outer casing, an impeller mounted for rotation Within the casing, inlet and outlet conduit means for conducting fluid to and from said impeller, and second magnetic means associated with the impeller and magnetically coupled with the first magnetic means for rotating the impeller therewith, each of said first and second magnetic means consisting essentially of an annular member of permanent magnet material, said members being axially aligned With one another and each comprising permanently magnetized pole piece projections of opposite polarity disposed in adjacent spaced relation.

5. A centrifugal pump comprising: a base assembly which includes a hermetically sealed housing substantial- 1y completely filled with oil, a motor mounted Within the housing and totally immersed in the oil, and first magnetic means connected for rotation by the motor Within the housing and having the greater portion thereof immersed in the oil; and a pump head assembly removably mounted on the base assembly, said pump head assembly including an outer casing, an impeller mounted for rotation Within the casing, inlet and outlet conduit means for conducting fluid to and from said impeller, and second magnetic means associated with the impeller and magnetically coupled with the first magnetic means for rotat ing the impeller therewith, at least one of said magnetic means consisting essentially of an annular member of permanent magnet material having axially projecting pole pieces magnetized in an axial direction at a plurality of spaced points about the periphery thereof.

ii. A centrifugal pump comprising: a base assembly which includes a hermetically sealed housing, a motor mounted Within the housing, first magnetic means connected for rotation by the motor and disposed within the housing, and a bearing pin projecting from an outer surface of the housing; and a pump head assembly removab'ly mounted on the base assembly, said pump head assembly including an outer casing, an impeller for pumpin g fluid through the outer casing, a sleeve bearing mounting said impeller on said bearing pin for rotation Wltllll'l said casing, inlet and outlet conduit means formed 1n said casing .for conducting fluid to and from said impeller, second magnetic means associated with the impeller and magnetically coupled with the first magnetic means for rotating the impeller therewith, at least one of said magnetic means consisting essentially of an annular member of permanent magnet material having axially projecting pole pieces magnetized in an axial direction at a plurality of spaced points about the periphery thereof, and additional conduit means formed in the sleeve bearing and communicating the interior of the sleeve bearing with the inlet of the impeller for circulating lubricating fluid between .the adjacent surfaces of the bearing and bearing pin.

A pump comprisin' a pumping chamber having an inlet and outlet, a relatively thin rigid diaphragm closing said chamber, rotary pumping means Within said chamher and ro-tatably carried and Wholly supported by said diaphragm and rota-table magnetic means adjoining the outer surface of said diaphragm for imparting rotation to said rotary pumping means.

ii. A fluid pump comprising an essentially cylindrical housing having an end Wall and a fluid inlet and outlet, a diaphragm overlying the other end of said housing, a cantilever shaft carried by said diaphragm in perpendicular relation thereto and disposed within said housing, rotary pumping means including a magnetic element rotatably carried by said shaft, annular means secured to said other end of said housing to firmly secure the diaphragm to the housing and a rotatable magnet carried in close proximity to the outer side of said diaphragm whereby rotation of the last said magnet will impart rotation to said rotary pumping means.

li'ieterences Cited by the Examiner UNITED STATE; PATENTS 2,603,671 7/52 Burns et al 22O81 2,646,001 7/53 Ray 103*87 2,810,349 10/57 Zozolin 10387 2,824,664 2/58 French et al 22081 2,951,613 9/60 Hardigg 22081 ROfiERT M. WALKER, Primary Examiner.

LAURENCE V. EFNER, JOSEPH H. BRANSON, 1a.,

Examiners. 

1. A CENTRIFUGAL PUMP COMPRISING: A BASE ASSEMBLY WHICH INCLUDES A HERMETALLY SEALED HOUSING SUBSTANTIALLY COMPLETELY FILLED WITH OIL, A MOTOR MOUNTED WITHIN THE HOUSING AND IMMERSED WITHIN THE OIL, AND FIRST MAGNETIC MEANS CONNECTED FOR ROTATION BY THE MOTOR AND DISPOSED WITHIN THE HOUSING; AND A PUMP HEAD ASSEMBLY REMOVABLY MOUNTED ON THE BASE ASSEMBLY, SAID PUMP HEAD ASSEMBLY INCLUDING AN OUTER CASING, AN IMPELLER MOUNTED FOR ROTATION WITHIN THE CASING, AN IMPELLER MOUNTED MEANS FOR CONDUCTING FLUID TO AND FROM SAID IMPELLER, AND SECOND MAGNETIC MEANS ASSOCIATED WITH THE IMPELLER AND MAGNETICALLY COUPLED WITH THE FIRST MAGMETIC MEANS FOR ROTATING THE IMPELLER THEREWITH, AT LEAST ONE OF SAID MAGNETIC MEANS CONSISTING ESSENTIALLY OF AN ANNULAR MEMBER OF PERMANENT MAGNET MATERIAL HAVING AXIALLY PROJECTING POLE PIECES MAGNETIZED IN AN AXIAL DIRECTION AT A PLURALITY OF SPACED POINTS ABOUT THE PERIPHERY THEREOF. 